ConstReaders disagree on such files: zip.js reads the last archive, as Info-ZIP unzip and Python's zipfile do,
whereas 7-Zip reads the first one and reports the rest as data after the end of the archive. The archive is
therefore ambiguous, and the entries reported here may not be the entries another tool reports. It is always
accompanied by WARNING_PREPENDED_DATA, which alone does not distinguish this case from a benign prefix.
Use strictness: "strict" to reject these archives instead, at the cost of also rejecting benign prefixes.
Warning reason: the data prepended before the zip file holds a central directory of its own, i.e. the zip file is preceded by another archive rather than by an arbitrary prefix such as a self-extracting stub (see ZipReader#warnings)